There are known spinning apparatuses for producing spun yarn by twisting fibers using a rotating air current, having a nozzle that applies a rotating air current to a sliver fed from a draft device, a hollow spindle and a needle shaped guide member having a tip opposed to the tip of the fiber introduction side of the hollow spindle.
In the conventional spinning apparatus, as shown in FIG. 3, a sliver L supplied via a sliver guide G is drafted by a draft device D composed of a back roller d1, a third roller d2, a second roller d3 with an apron and a front roller d4, and is then fed to a twist device T consisting of a nozzle member and a spindle member that can be contacted with and separated from each other, in which the sliver is formed into spun yarn Y, which is then passed through a spun yarn feed device H consisting of a nip roller h1 and a delivery roller h2 and a slab catcher Z. The yarn Y is then wound around a package w3 driven by a friction roller w1 and supported by a cradle am w2 in a winding section W.
The twist device T consisting of the nozzle member N and the spindle member S is described below with reference to FIG. 4.
n1 is a nozzle gripped by a nozzle housing n2 and a flange portion n3' of a nozzle outer frame n3, and mounted by the nozzle housing n2 and the nozzle outer frame n3 by coupling the nozzle housing n2 and the nozzle outer frame n3 using a bolt n4. n5 is an air chamber formed by the nozzle n1 and the nozzle housing n2, and air injection holes n7 are formed in the tangential direction of the inner circumferential surface of the nozzle n1 in such a way as to allow the air chamber n5 to communicate with a generally cylindrical hollow chamber n6 in the nozzle n1. A plurality of, for example, four air injection holes n7 are formed along the circumference direction of the nozzle n1. The nozzle member N is mainly composed of the nozzle n1, the nozzle housing n2 and the nozzle outer frame n3.
s1 is a non-rotatable hollow spindle mounted on a spindle supporting frame s2 and having a hollow passage s1', and s3 is a sliding frame mounted on the nozzle outer frame n3 and having a guide hole s4 in which a guide rod G is loosely fitted. The sliding frame s3 has at its approximate center a hole s3' into which part of the spindle supporting frame s2 and the end part of the spun yarn exit side of the hollow spindle s1 mounted on the spindle supporting frame s2 is inserted.
Furthermore, the sliding frame s3 has a plurality of, for example, three holes s5 formed horizontally at appropriate intervals, and a flange portion s6 having a bolt insertion hole s6' with a smaller diameter than the inner diameter of the hole s5 is swollen in the middle of the circumference of the hole s5. s7 is a protruding portion provided on the spindle supporting frame s2, the tip of which is inserted into the hole s5.
s8 is a bolt with a head s8' abutting the flange portion s6 swollen in extending across the hole s5 or located in proximity to the flange portion s6, a barrel s8" inserted into the bolt insertion hole s6' and a threaded tip screwed into the protruding portion s7 provided on the spindle supporting frame s2. s9 is a compression coil spring disposed between the flange portion s6 and the end surface of the protruding portion s7 provided on the spindle supporting frame s2. The spindle supporting frame s2 is coupled to the sliding frame s3 via the bolt s8, and the spindle supporting frame s2 and the sliding frame s3 are forced by the compression coil spring s9 to move apart.
s2' is an approximately disc-shaped fitting portion provided on the nozzle s1 side of the spindle supporting frame s2. The end of the spun yarn exit side of the hollow spindle s1 is shaped like a trumpet so as to guide the leading yarn that is passed through the hollow passage s1' of the hollow spindle s1 during a piecing operation.
s10 is a pin protruding from the side wall of the sliding frame s3 and fitted in a recessed portion v1 provided at the tip of an oscillating lever V that can be oscillated around a predetermined supporting point in the lateral direction in FIG. 4 by a piston rod (not shown in the drawing). Thus, the oscillating lever V can be moved leftward in FIG. 4 to move the spindle member S leftward along the guide rod G via the pin s10 fitted in the recessed portion v1 in the oscillating lever V, thereby separating the spindle member S from the nozzle member N. Conversely, the spindle member S can be moved rightward to fit the fitting portion s2' of the spindle member S in an opening n3" of the nozzle outer frame n3 of the nozzle member N, thereby allowing the spindle member S to be coupled to the nozzle member N, as shown in FIG. 4. d4' is a front bottom roller.
As shown in FIGS. 4 and 5, a fiber introduction member having a fiber introduction hole e1 with an approximately flat fiber guide surface e1' and inserted into a recessed portion n8 formed on the front roller d4 side of the nozzle n1 so as to be opposite to the tip s1" of the hollow spindle s1 having the hollow passage s1'. e2 is a needle shaped guide member mounted in the fiber introduction hole e1 and close to the tip s1" of the hollow spindle s1.
n9 is an air chamber provided in the nozzle member N and in communication with a suction duct via a hole (not shown in the drawing), and the suction duct is connected to an air suction device (not shown in the drawing) in order to maintain the air chamber n9 at a low negative pressure. Therefore, fly fibers generated in the hollow chamber n6 during producing the spun yarn Y are removed through the gap between the inner circumferential surface of the nozzle n1 and the outer circumferential surface of the hollow spindle s1.
A process for producing the spun yarn Y using the twist device T consisting of the nozzle member N and the spindle member S is described below.
The drafted sliver L fed from the front roller d4 of the draft device D is sucked into the fiber introduction hole e1 of the fiber introduction member E by a suction air current generated near the fiber introduction hole e1 by air jetted from the air injection holes n7 formed in the nozzle n1. Fibers f constituting the sliver L sucked into the fiber introduction hole e1 are fed along the approximately flat fiber guide surface e1' and guided around the needle shaped guide member e2 mounted on the spindle member S side of the fiber guide surface e1' while entering the approximately cylindrical hollow chamber n6. The fibers f constituting the sliver L sucked into the hollow chamber n6 are subjected to a rotating air current that is jetted from the air injection holes n7 and swirled over the outer circumference of the hollow spindle s1 at a high speed, and are separated from the sliver L while being twisted in the direction of the rotating air current. Part of the twisting applied by the rotating air current attempts to propagate toward the front roller d4, but the propagation is hindered by the needle shaped guide member e2 to prevent the sliver L fed from the front roller d4 from being twisted with the fibers. The twisted fibers f are formed sequentially into spun yarn Y, which is then passed through the hollow passage s1' of the hollow spindle s1 and fed toward the winding section W.
In the conventional spinning apparatus, since the needle shaped member e2 is disposed opposite to the tip s1" of the fiber introduction side of the hollow spindle s1 as shown in FIGS. 4 and 5, the transfer passage for the fibers f passing from the needle shaped guide member e2 to the hollow passage s1' of the hollow spindle s1 is narrow and may be blocked by leaves and other foreign matter contained in the sliver L, resulting in yarn breakage.
In addition, since the needle shaped member e2 is disposed opposite to the tip s1" of the fiber introduction side of the hollow spindle s1, the ballooning of the fibers f around the tip s1" of the hollow spindle s1 is significant, disturbing the fibers f and preventing uniform spun yarn Y from being produced.
Furthermore, since the needle shaped member e2 is disposed opposite to the tip s1" of the fiber introduction side of the hollow spindle s1, this prevents the leading yarn from being passed through the hollow passage s1' of the hollow spindle s1 and the fiber introduction hole e1 of the fiber introduction member E during a piecing operation.
Furthermore, since the needle shaped member e2 is disposed opposite to the tip s1" of the fiber introduction side of the hollow spindle s1, the gap between the needle shaped guide member e2 and the hollow passage s1' of the hollow spindle s1 is small, increasing the tension of the fibers f passing though this gap and resulting in hard spun yarn Y being produced. If the diameter of the hollow passage s1' of the hollow spindle s1 is increased to expand the gap between the needle shaped guide member e2 and the hollow passage s1' of the hollow spindle s1 in order to solve the above problem, then the fibers f become difficult to bundle, resulting in degraded spinning capability.
It is an object of the present invention to solve the above problems with the conventional spinning apparatus for spinning yarn using a rotating air current and to provide a spinning apparatus with an improved spinning capability.